Treatment of worn abrasive belts



June E, 943. n H, CQNRADY 2,320,569

TREATMENT OF WORN ABRASIVE BELTS Filed May 3, 19159 Patented June 1, 1,943l

TREATMENT' OF WORN ABRASIVE BELTS Hans Conrady, Kelkheim in Taunus, Germany; vested in the Alien Property Custodian Application May s, 1939, serial No. 271,619 In Germany May 2, 1938 1 Claim.

The present invention relates to a treatment of worn abrasive belts and has its particular field of application in a method of renewing the usefulness of emery cloth, glass paper and sand paper belts for wood and metals.

Although not restricted thereto, the invention will be described in its application to a method of renewing the usefulness of Worn abrasive belts in which the abrasive has been bonded to the backing member by glue or similar material. In this treatment the abrasive belt is placed upon pulleys, made to move about them in a closed chamber, cleaned in dry state and subsequently subjected to the action of moist heat to melt the glue bond. The grit bearing surface of the abrasive belt moving about the pulleys is then subjected to the action of a second brush and. While the glue bond is in a softened condition, the loose Worn abrasive on the belt is relocated to expose new sharp cutting faces on the abrasive grains.

In the accompanying drawing,

Fig. 1 is a side elevation of a mechanism for treating abrasive belts,

Fig. 2 is a sectional top view of this mechanism,

Fig. 3 is a view in top elevation of some component details, and

Fig. 4 is a view in side elevation of another detail.

Referring tc the drawing, the worn abrasive belt is placed in a chamber closable by cover 'l with hinge 'Ia upon the fixed pulleys 2 and 3 and the longitudinally adjustable pulley 4. 'I'he pulley 2 is driven by a motor I5 to move the belt about the pulleys and between the heating members 5 and 6 closed by a wall opposite to cover 1. The abrasive belt is subjected to a preliminary dry cleaning by the aid of the rotary brush l and then to the action of moist heat produced by a clean or glue water spray entering the heated chamber through the nozzle 8 at the opening 9 of the pulley 3. The opening 9 is subsequently closed by the partially hooded rotary brush IIJ with peep hole I3a so that the abrasive belt runs in the closed and heated chamber I3. A further supply of steam is admitted through the valve I I, and a gauge I2 indicates the moist heat which may be regulated to suit prevailing conditions. The rotary brush I Il generally consists of galvanized steel wires 0.2 mm. thick and 20 mm. long which are reenforced by interwoven wires.

As soon as temperature and moisture condition will have sufficiently softened the glue bond, the rotary brush I0 is made to contact with the abrasive belt by means the lever I 4. The grit bearing surface of the abrasive belt will then be subjected tothe action of this rotary brush I0 while the belt is moving about the pulleys to relocate the loose and worn abrasive thereby exposing new sharp cutting faces on the abrasive grains. The abrasive belt will then be cooled and dried to recement the relocated abrasive grains thereon.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

In the method of renewing the usefulness of worn abrasive belts in which the abrasive has been bonded to the backing member by glue or other similar material, the steps comprising placing said belt upon pulleys in a closable heated chamber, subjecting said belt to a preliminary dry cleaning by a rotary brush and then to the action of moist heat to melt the glue bond. causing the belt to move about said pulleys, subjecting the grit bearing face of said belt to the action of a second rotary brush while the belt is moving about said pulleys and while said bond is in a softened condition to relocate the Worn abrasive on said belt thereby exposing new sharp cutting faces on the abrasive grains and subsequently cooling and drying said belt to recement the relocated abrasive grains thereon.

HANS CONRADY. 

